Three-dimensional display has been considered as an ultimate dream of display technology development, many companies and research institutions have been dedicated to research in this field over the years. Developed countries such as Japan, Europe, America, South Korea and other regions have been involved in research on the three-dimensional display technology in early 1980s, and began to gradually acquire different levels of research results in the 1990s, and have developed two types of three-dimensional display technology systems including one system that requires wearing three-dimensional glasses and the other system that does not require wearing the three-dimensional glasses.
The three-dimensional display technology system that requires wearing the three-dimensional glasses may be divided into an early anaglyph-type three-dimensional display technology, nowadays shutter-type three-dimensional display technology, and nowadays polarization-type three-dimensional display technology. For the shutter-type and the polarization-type three-dimensional display technologies that are widely used nowadays, a wearer is required to wear corresponding three-dimensional glasses. For any type of three-dimensional glasses, the wearer needs to correctly wear the glasses and maintain a correct head posture when watching, so that a transmission axis of each lens is properly angled with a polarization axis of an image of a display device.
Specifically, the polarization-type three-dimensional display technology utilizes polarization properties of light. A three-dimensional display apparatus alternately displays polarized lights that have polarization directions perpendicular to each other based on left and right eye images. When the left eye image is displayed, a transmission axis direction of the left lens is parallel to a polarization axis of the left eye image and the left eye image is visible to the left eye. At this time, a transmission axis direction of the right lens is perpendicular to the polarization axis of the left eye image and the left eye image is invisible to the right eye. When the right eye image is displayed, the situation is exactly opposite to above-described situation.
For the shutter-type three-dimensional display technology, a three-dimensional display apparatus divides each image frame into two parts to form two groups of images respectively corresponding to the left eye and the right eye, and alternately display the two groups of images in the same polarization direction in a continuous manner. At the same time, an infrared signal transmitter equipped to the three-dimensional display apparatus synchronously controls switches of corresponding left and right shutter-type lenses of the three-dimensional glasses. The shutter-type lens usually utilizes a principle that liquid crystal molecules are rearranged when an electric voltage is applied so as to change a transparency of a liquid crystal panel, so that each of the left eye and the right eye may see a corresponding image at a correct moment. In fact, the left and right shutter-type lenses of the shutter-type three-dimensional glasses are polarized lenses, and a transmission axis of the left lens is the same with a transmission axis of the right lens. Under a correct viewing posture, the transmission axes of the left and right lenses are parallel to a polarized axis of a polarized light emitted from the corresponding three-dimensional display apparatus.
According to above-described two types of three-dimensional display technologies, the two eyes of the wearer view different images that switch in a high speed, which causes an illusion in the brain of the wearer so that three-dimensional images are viewed.
However, the above-described prior art has following disadvantages: the wearer needs to maintain correct head posture when viewing the images; when the glasses rotate by an angle as the head swings towards the left or right, the transmission axes of the lenses fail to maintain proper angles with the polarized axes of images of the display apparatus. Thus, the wearer cannot get good viewing effect and may feel dizzy and fatigued.